Like humans, polar bears don't usually eat each other. But like the humans who survived the 1972 plane crash in the Andes that the 1993 movie Alive was based on, when faced with the choice of starvation or cannibalism, polar bears will resort to making a meal out of one of their buddies.
Polar bear cannibalism and infanticide has been witnessed a number of times over recent years, as the Arctic ice-sheets (the polar bear's natural hunting grounds) have shrunk and food for the world's biggest and whitest bear species has become increasingly scarce.
Wildlife photographer Jenny Ross just released these gruesome photos she took in the Svalbard Archipelago, Norway in 2010.
Content warning: some of Ross's photos are pretty rough.